Error VBOX_E_OBJECT_IN_USE (0x80BB000C)

[Donja]

Hello,
I am using VirtualBox 4.3.6 running on Windows 7 SP1

If have a guest OS WIndows Vista (among 4 others). When a start the VirtualBox Manager I get for this quest the error:

Cannot attach medium 'C:\Program Files\Oracle\VirtualBox\VBoxGuestAdditions.iso' {386e6bbc-6a93-44b8-954d-d5c45c5bb661}: medium is already associated with the current state of machine uuid {2164b9c9-5f5c-4907-916e-ecb4c6b53218}!.

Resultaatcode: VBOX_E_OBJECT_IN_USE (0x80BB000C)
Component: Medium
Interface: IMedium {05f2bbb6-a3a6-4fb9-9b49-6d0dda7142ac}

I was saving the state of the machine, but shutted down the host too early I think
Please help!

[Donja]

I delete the machine in the VM Manager (not the VDI itself) and created a new one. To my surprise that fixed it. Miracles still exists!